Dominosa
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Tile the rectangle with dominoes (1&times;2 rectangles) so that
every possible domino appears exactly once (that is, every possible
pair of numbers, including doubles).
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Click between two adjacent numbers to place or remove a domino.
Right-click to place a line between numbers if you think a domino
definitely cannot go there. Dominoes light up red if two identical
ones appear on the grid.
